Making composite stone.



Patented December 15, 1903.

E new this CLAUDE A. 0. nosntn on NEW YORK, t. Y., ASSIGNOR TO conrosrrn [STONE AND BRICK COMPANY, A CORPORATION or DELAWARE.

MAKING COMPGSITE STUNE.

' SPECIFICATION formingpart of Letters Patent No. 747,228, dated December 15, 1903.

' 7 Application filed January 28, 1903. Serial No. 140,836. (No speoimensd ;.5."0 all whom it may concern:

Be it known that I, CLAUDE A; o. RosnLL,

a citizen of the United States, residing at New York, State of newand useful posite Stone, fication.

.This invention relates to the manufacture of essentially, of

New York, have invented a Improvement in Making Oomof which the following is a specicomposite stone consisting, sand and lime and in which the binding effect of the lime is supplemented by the use of an alkaline compound. The particular alkaline compound I use is sodium hydrate or caustic soda.

In making'composite stone according to this process I proceed as follows: To a solution of caustic soda quicklime is added until a dry mixture of sodium hydrate and calcium hydrate is produced. This mixture is mixed with any available form of silica or material in which silica preponderates, such as ordinary sand in a dry state. Sufficient moisture is added to make thecomposition capable of being shaped by mechanical pressure in a mold, the moisture required for the purpose being only very slight. After the composition hasbeen thus prepared it is formed into articles of desired shape, and these are indurated in any preferred IllLl1D6l,'I10 novelty being claimed for this feature of the process.

The percentage of lime and soda used is as follows: from three to six per cent. of slaked lime and one-fifth to one per cent. of caustic soda counted as dry sodium hydrate. These proportions are by weight and are an illustration, nota limitation. The amount of water used in the caustic-soda solution is varied with the amount of quicklime that is to be slaked therein.

In place of applying all the lime and all the caustic soda as a dry mixture of lime and caustic soda only part of the quicklime to be used may be added to the caustic-soda solution to form a dry mixture of lime and caustic soda, the other portion of the quicklime being slaked separately with water or steam in the usual way, and the sand, slaked lime, and a dry mixture of lime and will proceed exactly as before described.

which an increase of the caustic soda may then be mixed, after which the operation This process is more particularly adapted for the making of indurat'ed sand bricks of very superior quality.

In place of applying the caustic sodain the form of a dry mixture of lime and caustic soda it may also be used in the form of a solution, in which case the-main ingredientssilica and slaked limeare moistened with the caustic-soda solution previous to molding. Again, in place of using the caustic soda in the body of the composition it may he applied as a solution to the surface of the molded articles, in which case the articles may preferably first be partly indurated, after which the caustic-soda solution is applied to their surface and the induration may then becompleted. The effect of the use of the causticsoda solution on the surface of the molded articles'made of sand and lime and which have a more or less friable surface is a surface-hardening, which removes or diminishes theobjection of friability. Itis evident that the caustic-soda solution may also be applied to a partly-indurated composition made of sand, caustic soda, and slaked lime and in general to any partly-indurated articles of surface hardness may be desired. Likewise the caustic soda may also be applied dissolved in milk of lime to any partly-indurated articles to increase the surface hardness.

The simultaneous use of caustic soda and lime has the advantage that the soda and the lime readily form an insoluble calciumsodium silicate, which is the result aimed at whenever an alkaline compound of any kind is used with lime and sand.

The partial induratiou referred to need only be carried so far that the articles treated do not disintegrate when immersed or soaked in the caustic-soda solution with or without the lime.

What I claim as new is 1. In the art of making artificial stone, the improvement which consists in mixing sand, slaked lime and caustic soda, forming the mixture into articles of desired shape, and then indurating the same.

2. .In the art of making artificial stone, the improvement which consists in mixing sand, and a dry mixture of lime and caustic soda,

cles of desired shape, and then indurating thesame.

4. In the art of making artificial stone, the

no improvement which consists in mixing sand -with a suitable binding agent, forming the mixture into articles of desired shape, partly indurating said articles, then applying to them a solution of caustic soda, and thencompleting the indnration.

5. In the art of making artificial stone, the improvement which consists in mixing sand, slaked lime and caustic soda, forming the mixture into articles of desired shape, partly ac indurating the same, then applying to them a solution of caustic soda, and then completing'the induratiome wanes 6. In the art of making artificial stone, the improvement which consists. in' mixing the constituent ingredients, forming the mixture into articles of desired shape, partly iudurating the articles, applying tn them a solution of caustic soda. and then completing theinduration.

7. In the art of making artificial stone, the

improvement which consists in mixing the constituent ingredients, forming the mixture into articles of desired shape, partly indurating the articles, applying to them milk of lime containing caustic soda in solution and then completing the induration.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 26th day of January, 1903. 4

- CLAUDE A. 0. ROSELL.

Witnesses:

LYNN S. Lnn'r, B. F. KEINARD. 

